电极结构对AlGaInP-LED阵列电流分布的影响

以AlGaInP-LED外延片为基片,设计了分辨率为320×240、像素尺寸为100 μm×100 μm的微型LED阵列。针对目前LED阵列普遍存在的电流分布不均匀的问题,建立了内部电流分布模型,研究了电极结构、电极尺寸及电极间距等不同因素对LED电流分布造成的影响。在单条形电极结构的基础上进行优化,综合考虑不透明电极的遮光效应等因素得到三条形电极结构为最优的电极结构,该电极结构的LED有源层均匀发光面积比未经优化的单条形电极提高了65.02%,比双条形电极提高25.63%,有效提高了微型LED阵列的出光效率,对改善LED芯片发光均匀性具有参考意义。

Effects of Electrode Structure on The Current Distribution of AlGaInP-LED Array

An array of 320×240 micro-LED is designed based on AlGaInP epitaxial wafer. The pixel size is 100 μm×100 μm.The optical properties of LED array are affected by the current crowding effect, which is a universal problem in LED array. By simulating the active layer current distribution, effects of some factors including electrode structure,width of electrode and distance between electrodes on the current distribution of LED array are studied. The tri-strip electrode is proposed as an optimized structure of the top electrode. Considering some important details such as the light shading effect, the tri-strip electrode is the best electrode shape comparing with one-strip electrode and bi-strip electrode. The optimized electrode leads to the more uniform current spreading.The uniform lighting area of active layer increase 65.02% and 25.63% than that one strip electrode and bi-strip electrode, respectively. The light emission efficiency of the micro-LED array can be improved.